Chennai to Andaman by ship or boat

I am thinking of taking a ship/boat from Chennai to Andaman Islands and I have a few things to ask:

1. Do I need any special permissions to make this trip?
2. How often a ship/boat leaves from Chennai to Andaman?
3. How can I arrange my trip from Chennai to Andaman?
4. Any good place to visit in Andaman Islands?
5. How safe it is?
6. Any tips or anything else I need to know before making this trip

I made this trip from Chennai to Andaman way back in year 2009 and it was real fun, I remember paying around INR. 7000 for Deluxe cabin in M.V. Akbar and it took around 64 hours from Chennai to Andaman.

I never heard of any accident so far so I think it's totally alright, any commercial ship leaves only after getting the accurate weather conditions otherwise they delay the trip. If you are very much concerned about the safe then prefer not to make this trip as no one can take a guarantee of 100% safety in ocean.

I would recommend taking the sea route on your way in and take a flight for your return journey. There is also a ship that sails twice a week from Kolkata. You can find more information about getting to Andaman in this Andaman Nicobar travel guide.

2 nights and 3 days is a long time and I hear the basic bunks are jam packed and common toilets are not a good scene. If you value comfort then take a flight. Also the ship tickets do not include food and beverages so that is also an extra expense on top of the tickets. Deluxe cabin berth is upwards of Rs8000 and that is per person and there are I believe 4 berths in every cabin.